1. Field of the Invention
The invention relates to a releasable deck plate for use with a kayak or similar watercraft to allow the operator of the craft to quickly and safely evacuate the cockpit during an emergency.
2. Description of the Prior Art
The present invention provides a means by which the paddler can more easily remove his legs from the craft to avoid entrapment. This is achieved in the preferred embodiment through the introduction of a manually releasable, removable foredeck section into the kayak which, when removed, substantially increases the size of the cockpit. In order to be useful to the whitewater paddler, the removable foredeck should fulfill three criteria. First, it must be rigidly attached to the rest of the boat during normal operation in order to provide structural strength to the kayak. This also allows the paddler to brace his knees for maneuvering and Eskimo rolling. Secondly, the removable foredeck must be manually releasable in such a way as to separate from the craft only when actuated by the paddler. Thirdly, the removable foredeck must be easily releasable by the paddler during common pinning situations.
Prior art relating to emergency egress from kayak-type craft fail to meet these requirements. The patent of Brock (U.S. Pat. No. 1,792,140) describes a sectional foredeck which opens automatically when the boat turns upside down. The patent of Von Moltke (DM 536,699) describes a flexible, sealed spraydeck which rolls open automatically when the boat is turned over. The patent of Hart (DM 507,952) describes a flexible deck with stiffeners which can be lifted up by the paddler and which also opens automatically when the boat is turned over. The patent of Masters (U.S. Pat. No. 4,520,747) describes a rigid deck, hinged at the front, and connected to the boat with flexible gaskets. The patent of MacKereth (GB 2 134 454 A) describes a rigid deck with a releasable system held in place by a cable system. The patent of Masters (U.S. Pat. No. 4,727,821) describes a detachable pod for the kayak operator to sit in.
All of these releasable deck systems suffer from severe shortcomings when applied to whitewater kayaks: 1) they can release inadvertently in non-emergency situations, (Brock, Hart, Von Moltke) and 2) they require a lifting force perpendicular to the plane of the removable foredeck section in order to release (Brock, Hart, MacKereth, Masters). These shortcomings are alleviated by the patents of Curtis et al. (U.S. Pat. No. 4,699,076;GB 2167353) and the present invention.
In devices which release automatically (Brock, Hart, Von Moltke), the paddler is forced to exit the craft and swim every time the craft is turned upside down. This can be extremely hazardous for the paddler. In addition, during normal whitewater paddling, the paddler and the kayak are routinely subjected to a wide variety of forces which are unpredictable and at times severe. The paddler is constantly being thrust up (or is bracing) against the underside of the foredeck, thereby causing such systems to release inadvertently. Inadvertent release of any sort is prevented by both the patents of Curtis et al. and the present invention, which describe a slidably releasable foredeck section which can only be released when actuated by the paddler.
Prior art which requires a lifting force perpendicular to the releasable foredeck section (Brock, Hart, MacKereth, Masters) fail to allow the paddler to exit his boat in many of the common whitewater pinning situations where oncoming water is pressing against the releasable foredeck section, a situation known as the broach. A broach occurs when the kayak is pressed broadside against an obstruction by the force of the current. In this situation the deck of the kayak often faces upstream, with the force of the current pressing directly against the deck surface. In the presence of such a force, (e.g. 300 kilograms of force on a boat with a current speed of 10 kilometers per hour), it is highly unlikely that a paddler would be able to actuate a device which requires that the foredeck cover be lifted in the direction of the oncoming current. The patents of Curtis et al. and the present invention, however, do not require a lifting force for release. Rather, both utilize a release force parallel to the deck for easy release even when a significant force is applied directly down onto the foredeck.
Like the patents of Curtis et al., the present invention describes a slidably releasable, manually operated releasable foredeck system. However, while Curtis et al. utilizes a multiplicity of attachment/release fasteners to connect the releasable foredeck section to the watercraft, the present invention is dramatically simpler, utilizing only a single fastener means which can be molded integrally with the watercraft. This single fastener means is more easily attached to the craft since only one fastener needs to be properly aligned. Moreover, the single fastener has superior water resistance because of the convoluted path that the water must travel in order to enter the watercraft. Finally, the shape of the single fastener means along the periphery of the extended cockpit opening augments the structural rigidity of the entire deck of the watercraft and of the releasable foredeck section.